java what is nullpointerexception code example

Example 1: NullPointerException

TestObject a = new TestObject();String b = a.getTestResult();b.toString();

Example 2: nullpointerexception java

Integer num;
num = new Integer(10);

Example 3: nullpointerexception java

int x;
x = 10;

Example 4: nullpointerexception

public class MyClass{
private Object iAmNowNull;//This is null by default
    private Object iAmInitialized=new Object();
    public void test(){
    	System.out.println(iAmInitialized.toString());//prints that object
        System.out.println(iAmNull.toString());//throws a NullPointerException
}

Example 5: nullpointerexception

public class MyClass{
	private Object iAmNull;//This is null by default
    private Object iAmInitialized=new Object();
    public void test(){
    	System.out.println(iAmInitialized.toString());//prints that object
        System.out.println(iAmNull.toString());//throws a NullPointerException
    }
}